Infragistics UltraTabbedMdiManager标签重叠与面板下移问题求助

I’ve run into similar quirks with UltraTabbedMdiManager in v14.1 before, so here are some targeted workarounds you can try before committing to a version upgrade:

Problem 1: Tab Panel Shifts Down on Second Tab Creation #

Your temporary fix of disabling/enabling tabs works, but we can refine it to be more efficient:

• Refresh Layout Directly: After creating the new MDI child form, call ultraTabbedMdiManager1.RefreshLayout() immediately, followed by yourMdiContainer.PerformLayout(). This forces the manager to recalculate panel positioning without touching all tabs.
• Lock Child Form Position: Set the new form’s StartPosition to FormStartPosition.Manual and explicitly set Location = Point.Empty when initializing. Auto-positioning logic in v14.1 sometimes conflicts with MDI layout on the second tab.
• Adjust Focus Timing: Instead of activating the new tab right away, first set ultraTabbedMdiManager1.ActiveTab = null, then create and show the form, then reactivate the new tab. This avoids race conditions in focus handling.

Problem 2: Child Form Shifts & Stale Control Overlap #

Since you can’t use ShowInTaskbar = false (due to Application.OpenForms dependency), try these alternatives:

• Force Child Form Z-Order & Redraw: After showing the new form, call newForm.BringToFront() followed by newForm.Invalidate(true) and newForm.Update(). This ensures the new form is rendered on top and clears any stale control artifacts.
• Explicitly Attach to Container: When creating the child form, explicitly set newForm.MdiParent = yourMdiContainer and add it to the container’s controls with yourMdiContainer.Controls.Add(newForm) (even though MDI should handle this, v14.1 sometimes misses this step dynamically).
• Leverage TabSelected Event: Hook into ultraTabbedMdiManager1.TabSelected, and in the handler, call e.Tab.MdiChild.Refresh() to force a redraw whenever a tab is activated.

Multiple UltraTabbedMdiManager Instances #

Yes, v14.1 has known issues with multiple MdiManagers coexisting in the same application, especially when nested in different containers. To mitigate:

• Isolate Managers: Ensure each MdiManager has a unique MdiParent container, and never share child forms between managers.
• Dock Containers Properly: Set each manager’s parent container to Dock = DockStyle.Fill to eliminate layout gaps that can trigger rendering bugs.
• Avoid Nested Managers: If possible, don’t nest MdiManagers inside other MdiManagers or complex container controls—this amplifies layout conflicts in older Infragistics versions.

If none of these work, a last-resort trick is to add a tiny delay before activating the new tab (using Task.Delay(10).ContinueWith(t => this.Invoke(() => ultraTabbedMdiManager1.ActiveTab = newTab))). This gives the UI thread time to finish rendering before handling focus, which fixes many timing-related glitches in v14.1.

内容的提问来源于stack exchange，提问作者amundell